[The Buddha said to Sāriputra,] “Just as the elder at firstattracted his children with the three carriages andafterward gave them just one great carriage decorated with jewels, which was the safest and most comfortablecarriage, he is not guilty of falsehood. So it is with theTathāgata: there is no falsehood in first guiding sentientbeings with the three vehicles and afterward liberatingthem with just the single Great Vehicle. Why? Becausethe Tathāgata has the Dharma storehouse of immeasurable wisdoms, powers, and fearlessnesses. Hecan give all sentient beings the teachings of the GreatVehicle but not all are able to receive it. For this reason,Sāriputra, you should understand that the Buddhas usethe power of skillful means to adapt the oneBuddha-Vehicle into three.”
The Lotus Sutra
Translation of the scriptural passage is based upon the rendition ofGene Reeves, The Lotus Sutra: A Contemporary Translation of a Buddhist Classics, (Boston: Wisdom Publications, 2008), 118.
This means that originally there is no such thing as theThree-Vehicle Bodhi. The Three-Vehicle Bodhi is but anexpedient teaching. If the Buddha did not apply skillful means to expound the Great Vehicle in three distinctways but taught the Great Vehicle straightaway, it wouldbe incomprehensible to sentient beings. The purpose of teaching the Three-Vehicle Bodhi is to help sentientbeings understand the contents of the ultimateBuddhahood in the one and only Buddha-Vehicle. Butbecause sentient beings are unable to grasp this teachingand are fearful of the suffering of cyclic birth-and-death,the one Buddha-Vehicle was adapted into three vehicles.Yet, the ultimate purpose of teaching sentient beings tolearn and practice the Three-Vehicle Bodhi is to enablethem to receive the most wondrous and unsurpassed one and only Buddha-Vehicle.
A Discourse on the Lotus Sutra, vol. 5, p. 50.